1 (Slip Opin i o n) OCTOBER T ERM, 20 10 Sy llabu s N O TE : Wh er e it i s feas ibl e , a s y llab u s (h ead n ot e) wil lbe rel e as ed , as is bein g d o n e incon n ecti onwithth is cas e , a tth e ti meth e op in i o n is is s u ed

. Th e s y ll abu s con s titu tes n o p a rt of th e op in i o nof th eC o u r t bu t h a s be en pre p are dbyt h e Re po rte ro f De ci sio n s fo r t h e co nveni e nce of t h e reade r . Se e United Statesv. Detroit Timbe r& Lumb er Co., 200U. S

. 3 21, 337

. 

# SUPREME CO URT O FTHE UNI TED STATES
Sy llabu s 

### SMITH ET AL


### . v . BAY ER C O RP. CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE EIGHTH CIRCUIT No. 09–1 20 5. Ar g u ed Janu a r y18, 2011 —Dec ided Ju ne 16, 201 1 Res p ondent(Ba y er) m o vedin Federa l Di s t rictCourtfor a ninj u nct i on

ordering aWe s tVirginia s t at e courtnott ocons ider am o tion for cla ss certification filed by petit i o n ers (S mith), who wer eplaintiffs in the sta t e-c o ur t ac tion. Bay e r though t s u ch a ninj unct i on wa rra nt ed b e ca us e, in a s e pa ra t ecas e , Ba ye r had pe rsuaded the same Federal Dis t rictCourt t odeny asim ila r clas s - cert ifica t ion m o t i on t h a thad been filed against Bayer by a differe nt pl aintiff, George McCollins. The District Court had denied McCo llins’ certification motion under Fed. Rule Civ. Proc. 23.

The cou r tgr a n t e d Ba yer’s req u es ted injunc tion ag ainst the stat e court p r oceedi n gs, holding th at its de nial of certification in McCollins’ case precluded litiga t ion of the cert ificat ion issue in Smith’s ca se. The Cour t of Appeal s forthe Eigh th Cir c uit affir m ed. It fir s t not e d that the Anti-Injunc tion Ac t(Ac t) g e ner a llypr ohibits feder a l c o ur ts from enjoining state court pr oceedings

. But itfound that the Ac t’ s r e litigat ion exception authoriz ed this inj unction b e ca us e or dina ry rules of issue preclusion barred Smith from see k ing certification of his pro

posed c l a ss. I nso doin g , th e c o urt concl u ded tha tSmith wa s invok

in ga State Ru le, W. Va. Ru le Civ

. Pr oc . 23, th at was su ffic i en tly simi lar to the Federal Rule McCollin s hadinvoked, such that the cer

tification issues presen ted in the two c a ses wer ethe same

. The c o ur t further held th at Smith, as an unnamed member of McCollins’ puta

tive class actio n , co uld be bound bythejudgment in McCollins’ case. Held: In enjoining the state court from considering Smit h’s class certif i

cation request, the federal court ex ceeded its authority under the “re

litig at ionex c e ption” to th e Ac t. Pp. 5–18.

(a) Under that Act, a federal cour t “maynot gr ant an injunc tion to s t a yproceedings in a S t a t e courtexcept” in ra re ca s e s , when ne ces -2 SM ITH v. BAYER CORP. Sy llabu s
sar yto “pr o tec toreffec t ua te [the feder a l c o ur t’ s] judgments.” 2 8 U. S. C. §2283

. Th e Ac t’ s “spec i fic a llydefin e d ex c e ption s ,” Atlanti c Coast Line R. Co. v. Locom o tive Engi ne ers , 398 U. S. 2 81, 28 6, “ar e narrow and are ‘not [to] be e n largedby loose statutory construction,’ ” Chick Kam Ch oo v. Exxon Corp. , 486 U. S. 14 0, 1 46. I n deed, “[a]n y dou b ts as to t h e pr opr i ety of a feder a l in ju n c tionag ainst st ate c o u r t proceedings s h ould be resolved in fav o rof per m ittingthe state c o ur ts to proceed.” Atlantic Coast Line R. Co., 3 98 U. S., at 29 7. Th e ex c e p tion at issue i nthis case, k n own as the “ r elitigation ex ception,” au

thorizes an injunction to prevent state lit igatio nof a c l aim orissu e “that pr ev ious lywas pr esented to an d decided by the fe deral court.” Chick Kam Choo, 486 U. S., at 1 47. Th is e x c e ptionis desig n ed to im

plement “well

- recognized co ncepts” of claim and issue preclusion. Ibid. Beca us e deciding whe t her a n d how prior litiga t ion ha s preclu

sive effect is usually the ba il iwick of the se cond court

—h e re, t h e Wes t Virginia court—every benef i t of the dou b t g oes towar dthe st ate court, see Atla ntic Coas t Li ne , 398 U. S., at 28 7, 297; a nin ju nc tion ca n is s u e only if preclus i o nis clea r b e yond pera dven t u re. For t h e federa l court ’ s cla s s - a c t i on det e rm ina t ion to preclude t h e s t a t e court ’ s adjudic a t i on o f Sm ith’ s mo ti on, at le as t t w o c o nditions must be met. Fir s t, the is su e the feder a l c o ur t de cided must be the same as the one presented in the state tribu n al. An d s e cond, S m ith mu s thave b een a par t yto the feder a l suit or must fa l lwithin one of a few discrete ex

c e ption s to th e g e n e r a l r u le a g ain s t bin d in gn o n p ar ties. Pp. 5–7.

(b) The issue the federal co urt de c i ded was not the same as the one presented in the state tr ib unal. This case is lit tle more than a rerun of Chick Kam Choo. There, a federal court di s m is sed a s u it involving Singapore law on forum no n conv eni e n s grounds and then enjoined the pla i ntiff from purs uingthe “sa m e ” c l aim inTex a s st ate c o u r t. How e v e r, becau s e th e leg a l stan dar d s for forum non co nveni e n sdif

fered in the t w o courts, the issues b e fore t h os e court s differed, m a k

ing a ninj u n c t i on unwa rra nt ed. Here, S m it h’s propos ed cla s s m i r rored McCollins’, and the two suit s’ s u bstantive cl aims broadly overlapped. B u t the federal court adjudicated McCollins’ certification motion under Federal Rule 23, wher eas the state court was poised to consider Smith’s proposed class under W. Va. Rule 2 3

. And the St at e Supreme Court has generally stated that i twill not nece ssarily inter

pr et its Ru le 23 as c o ter m i n ou s withthe Federal Rule. Absentclea r evidence that the state courts had adopte d an approach to State Rule 23 tracking the federal co urt’s analysis in McCo llins’ case, this Court c o uld not c o nclude that theywould inter p ret theirRule t h e same way a n d, thus , could not tell wh ether the certifica t ion is s u es in the two courts were th e s a me. Tha tuncer tainty would preclude an injunc

tion. And indeed, the case again s t an injunction here is even3 Cite as: 56 4 U

. S. ____ (2011) Sy llabu s stronger, because the State Supr eme Court has ex pressly di sap proved theapproach to Ru le 23(b)(3)’s predominance requirement embr ac ed byth e Feder a l Distr i c tCou r t. Pp. 8–12.

(c) TheDistrict Court’s injuncti on was independently improper be

ca us e S m ith wa s not apa r t y to the federa l s u it a n d wa s not covered b ya n y ex ception to the r u le a g a i ns t nonparty pre c lus i on. Gene ra lly, a par t y“is ‘ [ o]n ebyorag ain s t wh om a lawsu i t is br ou gh t,’ ” United States ex rel . Eisens t einv. City of New York , 556 U. S. ___, ___ , o r who “become[s] a party by interven tion, subst i tution, o rthir d-par t y practice,” Karcherv. May , 4 84 U. S. 72, 77. Th e defin i t i onof “par ty” ca nnotb es t ret c hed s ofa r a s t ocover apers on like S m it h, whom McCollins was denied leave to repres ent. The only exce ption to the rule a g a i ns t nonpa r ty precl u s i on po tentia lly relevant here is the ex

ception tha t binds non-na med memb ers of “ p roperly conduct e d cla s s ac tions” to ju dg ments ente red in such proceedings. T a

ylorv. Stur

gell , 553 U. S. 88 0, 89 4. Bu t McCollin s’ s u it was nota proper clas s a c t i on. Indee d , t h e ve ryru ling t h a tB a yer a r gu es s h o u ld have pre clus ive effectis t h e Dis t rict Court ’ s decision nott ocert ify aclas s . Ab s e nt certifica t ion of a clas s und er Fede ral Rule 23, the precondi

tion forbindi n gSmith was not met. Ne ither a proposed, nor a re

j e ct ed, cla s s act i on m a y bin dnonparties. See id., at 901. Bay e r c l aims tha tthis Cour t’ s app r oac hto c l ass ac tions would per m it c l ass c o unsel to tr y r e peatedlyto c e r t ifythe same c l ass si mplybyc h angi ng plaintiff s . Bu t principles of stare deci sis and c o mitya m ongc o ur ts g e ner a llysuffic eto mi tig a te the some time s subs tanti a l c o sts of s i mi

lar litiga t ion b r ought by different pl aintiff s . The right a pproach does not lie in b i nding no npa r ties to a judg ment. And to the ex tent c l ass actions raise special relit igation pr oblems, the federal Class Acti o n Fair n e ss Ac t of 2005 pr ov ide s a r e medyth at does n o t in v o lv e depar t

ing from theusual preclusi on r u les

. Pp. 1 2–18. 593 F. 3d 71 6, r e v e r s ed.

K

AGAN , J., delivered the o p inion of the Court, in w h ich R OBERTS , C. J., and S CALIA , K ENNEDY , G IN SB U R G , B RE Y E R , ALITO , and S OTOMAYOR , JJ., joined, an d in whi c h T HO MA S , J., join ed as to Par t s I an d II–A._________________

_________________ Cite as: 56 4 U

. S. ____ (2011) 1 Opinion of theCourt
NOTIC E : Th is op i n ionis subjec t to f o rma lrevi si onbef o r e publicat ioninth e p r eli m in ary p rin t of th e U n it edS t at es R e p o rts
. R e ad ers ar e r e qu es ted to n o tif yth e R e p o rt e rof D e c i s i on s , Su p r em e C o u rt of th e U n ited St at es , Wa s h

ington, D. C. 2054 3, of any typ o gra p hical or other f o rmal err o rs , in or der th atc o rr ect i on sm a y b e mad eb e f o r e th ep r e lim in aryp rin t go es t o p r es s . 

# SUPREME CO URT O FTHE UNI TED STATES
No. 09–1 20 5 

### KEITH SMITH, ET AL 

### ., PETITIONERS v. BAY ER C O RPORATIO N ON WRIT OF CERTIORARI TO THE UNITED STATES COURT OF APPEAL S FOR THE EIGHTH CIRCUIT [Ju n e16, 2011 ] 

### J USTICE 

### K AGAN

### delivered the opini o n of the Co urt.* In this case, a Federal District C o urt enjoined a stat e court from considering a plaintiff’s request to approve a class action. The Di strict Cour t did so because it had earlier denied a motion to certifya class in a related case, brought by a different plaintiff a g ainst the same defen

dant alleging similar claims. The federal court thought its injunction appropriate to prevent relitigation of the iss u e it had decided. We hold to the contrar y . Inis suin g this order to a state court, the federal court exceeded its authority under the “relitigation exception” to the Ant i -Injunction Act. Tha t statutory provision permits a federal courtto enjoin a sta t e pro c ee din g onl y in ra re case s, whe n ne ces s ary to “p ro t e c to reffectuate [the federal co urt’s] judg ments.” 2 8 U. S. C. §22 83. Here, thatstandar d was not met for two reasons. First, the issue presented in the state court wa s not identical to the one decided in the fed e ral tribunal. And second, the plaintiff in the state court did not hav e the requisite connection to the federal suit to be bound b y

——————

* J US TI CE T HOMAS joins Parts I and II–A of this opinion.2 SM ITH v. BAYER CORP. Opinion of theCourt 

### the DistrictCourt’s jud g ment. I Because the question before us involves the effect of a former adjudication on this case, we begin our statement of the facts not with this lawsuit, but with another. In August 2001, George McCollins sued respondent Baye r Corporation in the Cir c uit Court of Cabell County, West Virginia, as serting va rious st ate-law claims arising from Bayer’s sal e of an allegedly hazardous prescription drug called Bayc ol (which B a yer withd r ew from the market tha t same mont h). McCollins contended that Bayer had vio

lated West Virginia’s c o nsumer-protection statute and the company’s express and implied warranties by selling hi m a defective product. And pursuant to West Vi rginia Rule of Civil Procedure 23 (2011), McCollins asked the state court to cer t ify a class of West Virginia residents who had also purchased Baycol, so that the case could proceed as a class action. Approximately one month later, the suit n o w before us began in a different part of West Virginia. Petitioners Keith Smith and Shirley Sperlazza (Smith for short) filed state-law cl aims against Baye r, si milar to th ose raised in McCollins’ suit, in the Circuit Co urt of Brooke County, West Virgi n ia. And like McCollins, Smith asked the court to certify under West Virginia’s Rule 23 a c l ass of Bayc o l purchasers residing in the State. Neither Smith n o r McCollins knew about the other’s suit. In January 2002, Bayer removed McCollins’ case to the United Sta t es DistrictCourt for the Southern Distric t of West Virginia on the basis of diversity jurisdiction. See 28 U. S. C. §§1332, 1441. The case was then transferred to the Distric tof Minnesota pursuan t to apreex isting order of the Judicial Panel on Multi-District Liti gation, which had consoli d ated all federal suits involving Baycol (num

bering in the tens of thousands) before a s i ngle District3 Cite as: 56 4 U

. S. ____ (2011) Opinion of theCourt 

### Court Judge. See §1 407. Bayer, however, could not remove S m ith’s cas e to federal court b e cause Smith had sued s e veral West Virginia defendants in addition to Bayer, andso the suit lackedcomplete diversity. See §1441(b). 1 

### Smith’s suit thus remained inthe state court

house in Brook e County. Over the next six years, the two cases procee ded along their separate pretrial paths atro ughly the same pace. B y 2008, both courts were preparin g to turn to their respec

tive plaintif fs’ motions for cl ass ce rtification. The Federa l District Court was the firs t to reac h a decision. Applying Federal Ruleof Civil Procedure 23, 2

### the Dis

trict Court declined t o certify McCollins’ proposed clas s of West Virginia Bayco lpurchasers. The District Cour t’s reasoning proceeded in two steps. The court first ruled that, under West Virginia law, ea ch plaintiff would have to prove “actual injury” from his use of Baycol to recover. App. to Pet. for Cert. 44a. The court then h e ld that be

cause the necessary showing of harm woul d va ry from plaintiff to plaintiff, “individual issues of f a ct predom i

nate[d]” over issues c o mmon to all member s of the pro

posed class, and so the case was not suitable for class treatment. Id., at 45a. In the same order, the Distric t Court also dismissed McCollins’ claims onthe merits i n light of his failure to demonstra te physical injury from his use of Baycol. McColli ns chose no t to appeal. Although McCollins’ suit was now concluded, Bayer asked the District Co urt for ano ther order b a sed upon i t ,

——————

1 Th e Class Ac t i onFair n e ss Ac t of 2 005, 1 19 Sta t . 4, wh ic hpostda tes and therefore does not govern this law s u i t, n o w en ables a defen d an t to rem o ve t ofedera l courtcert a i n cla s s a c t i ons involving nondivers e par t ies. See 2 8U. S. C. §§1332(d), 145 3(b); see also infra, at 17.

2 Although McCollins had or iginally sought certification under West Virginia Rule of Civil Procedure 23 (201 1), feder a l pr oc edu r al r u les gover naca s et h a tha s b een rem o ved t ofedera l court

. S ee Shady Grov e Orthop edicAs sociate s , P

. A

. v. Allstat eIns. Co. , 559 U. S. ___ (2010).4 SM ITH v. BAYER CORP. Opinion of theCourt 

### this one af fecting Smith’s case i nWest Vir ginia. Ina motion—receipt of which firs t apprised Smith of McCol

lins’ suit—Bayer explained that the propo s ed class in Smith’s cas e was identical to the one the feder a l court had just rejecte d. Bayer t h erefore requested that the federal court enjoin the West Virginia s t ate court f r om hearing Smith’s mo tion to certi fy a class. Accordin g t o Bayer, th at order was appropria t e to prot ect the Di strict Cour t’s judgment in McCollin s’ suit denying class certification. The District Court agreed and granted the injunction. The Court of Appeals for the Eighth Circuitaffirmed. In re Baycol Prods. Litigation, 593 F. 3d 716 ( 2010). The court notedthat the An ti-Injunction Act generally prohib

its federal courts from enjoining state court proceedings. But the court held that the Act’s relitigation exception authorized the injuncti on here because ordinary rules of issue preclusion barred Smith fr om seeking certification of his proposed class. According to the court, Smith wa s invoking a similar clas s action rule as McCollins had used to seek certification “of the sa me c l ass” in a s u it alleging “the same legal theories,” id. , at 724; the issu e in the sta t e court there f ore was “sufficiently identical” to the one the federal court had decided to wa rr ant preclus i on, ibid

. In addition, the court held, the parties in the two proceeding s were sufficiently alike: Because Smith was a nunname d member of the class McCollin s had proposed, and because their “interests were aligned,” Smith was appropriate l y bound by the federal court’s judgm e nt. Ibid

. We granted certiorari, 561 U. S. __ (2010), because the order issued here impl icates two circuit splits arising from application of the Anti-Injun ction Act’s relitigation excep

tion. The first involves the requirement of preclusion law that a subs equent suit raise the “same issue” as a previo us case. 3

### The second concerns the scope of the rule that a

——————

3 Compare In re Baycol Prods. Litiga tion, 593 F. 3d 716 , 723 (CA 85 Cite as: 56 4 U

. S. ____ (2011) Opinion of theCourt 

### court’s judgment cannot bind non p arties. 4

### W e think the District Court erred o nboth grou nds when it gran ted t h e injunction, and we now reverse. II The Anti-Injunction Act, first enacted in 1793, provides that “A cou rt of t h e United S t ates may n o t gran t an injunc

tion to stay proceedin gs in a St ate court e x cept as expressly authorized by Act of Congress, or where necessary in aid of its jurisdicti on, or to protect or effectuate its judgments.” 28 U. S. C. §2283. The statute , we have recognized, “is a necess ary concom i

tant of the Framers’ decision toa u thorize, a n d Congress’ decision to implement, a dual system of federal and state courts.” Chic k Kam Ch oov. Exxon Corp. , 486 U. S. 1 40, 146 (1988). And the Act’s core message is one of resp ect for state co urts. The Act b r oadlycommands that those tribunals “shall remainfree from interference by federa l courts.” Atlantic Coast Lin eR. Co. v. Locomotive Engi

-

—————— 201 0) (c ase be low) (h oldin gth at tw o case s involve the same issue when
“ [t] he s t at e and federa l [cla s s ] cert ificat i o n rules .

. . are not signifi

c a ntlydiffer e nt”), with J. R. Clearwate r Inc. v. Ashla nd Chemical Co., 93 F. 3d 17 6, 180 (CA 5 1 9 9 6 ) (h oldin gth attwo c a se s im p lic ate d i ffer e n t issues even when “[the st at e rule] is modeled on .

. . the Federal Rules” bec a use a “[st ate] c o ur t might well ex erc i se [its] disc r e ti on in a differ e nt ma nner”).

4 Compar e 593 F. 3d, at 724(“[T]h e den i al of c l ass c e r t ific ationis b i nding on unna med [putative] cla s s memb ers ” b e ca u s e they a r e “in privity to [t he parties] i nthe prior action”) an d In re Brid ge stone/Firestone, Inc., Tires Prods. Liability Litigation, 333 F. 3d 7 6 3 , 768–7 69 (C A7 200 3) (s ame), with In re Fo rd Moto r Co., 471 F. 3d 12 3 3 , 124 5 (C A11 200 6) (h oldin gth at “[ t]h eden i al of c l ass c e r t ific ati o n” pr ev ents a c o ur t fr om “bindi ng” any o ne otherthan “the par t ies a ppear in gbefor eit”) an d In reGe ne ral Moto rs Cor p . Pick -Up Tr uckFuel Tank Prods. Liability Litigation, 134 F. 3d 13 3, 141 (C A3 1 9 9 8 ) (h oldin gth at putativ e“c las s member s ar e not par t ies” and so c a nnot be bound by a c o ur t’ s r u ling when “ther e is no cla s s pending”).6 SM ITH v. BAYER CORP. Opinion of theCourt


### neers , 398 U. S. 281, 282 (1970). That edict is subject to only “three specifically defined e x ceptions.” Id., at 28 6. And those exceptions, though designed for important purposes, “are narrow and are ‘not [to] be enlarged by loose statutory constru ction.’ ” Chi c k Kam Ch oo, 486 U. S., at 146 (qu o ting Atlan t ic Coast Line , 398 U. S., at 287; alteration in original). Indeed, “[a]ny doubts as to the propriety of a federal injunction against stat e court pro

ceedings should be resolved in favor of pe rmitting th e state courts to proceed.” Id., at 297. This case involves the last of the Act’s three exceptions, known as the relitigation except ion. That exception is de

signed to implement “well-recognized concep ts” of clai m and issue p r eclusion. Chick Kam Choo, 486 U. S., at 14 7. The provision authorizes an injunction to prevent state litigation of a claim or issue “that previously was pre

sented to and decided bythe federal court.” Ibid. But in applying this exception, we hav e taken special care to keep it “stri ct and narr o w.” Id. , at 148. After all, a court does not usually “get t o dictate to other court s the preclu

sion conseq uences of i t s own judgment.” 18 C. Wright, A. Miller, & E. Cooper, Federal Practice and Procedure §4405, p. 8 2 (2d ed. 2 002) (herei nafter Wright & Miller)

. Deciding whether and how prior litigation has preclusive effect is usually the bailiwick of the se cond cou rt (here, the one in West Virginia). So issuing an injunction under the relitigation exception is re sorting to heavy artillery. 5

### F o r that reason, every benefit of the doubt goes toward the state court, see Atlantic Coast Lin e , 398 U. S., at 287, 297; an injunction can issue only if preclusion is clear beyond

——————

5 Th at is e s pec i allyso bec a u s e an injunc tion is not the o n lywayto corre ctas t at e t r ia l court ’ s erroneo u s refus a l t ogive preclus ive effectt o a feder a l judg ment. As we hav enotedbefor e , “the sta t e appel l at e court s a n d ult i m a t e ly t h is Court” ca n re vi ew a n d re vers e s u ch a rulin g. See Atlantic Coast Line R. Co. v. Locom o ti ve Engin eers , 398U. S. 28 1, 287 (1 97 0).7 Cite as: 56 4 U

. S. ____ (2011) Opinion of theCourt 

### peradventu re. The question here is whether the federal court’s rejec

tion of McCollins’ prop osed class p r ecluded a l a ter adjudi

cation in state court of Smith’s certification motion. For the federal court’s dete rmination of the class issue to hav e this preclusive effect, at least two conditions must be met. 6 

### First, the is sue the federal courtde cided must be the same as the one presented in the state tribunal. See 18 Wright & Miller §4417, at 412. And second, Smith must have been a party to the federal suit, or else must fall within one of a few discrete ex ceptions to the general rule against binding nonparties. See 18A id., §4449, at 330. In fac t , as we will explain, the issues bef o re the two courts were not the same, and Smith was neither a party nor the ex ceptional kind of non p arty who can be bou n d. So th e courts below erred in findin g the certification issue pre

cluded, anderred all the more in thinking a ninjunction appropriate

. 7

——————

6 We have held t h a tfedera l com m o n la w governs t h e preclus ive effect of adecis i on of afederal courts i tt ing in divers it y. S ee Se mtek Int’l Inc. v. Lock he ed Martin Corp

. , 531 U. S. 49 7, 508 ( 2 0 01). Smi t has su mes t h a tfedera l com m o n la ws h ould here incorpora t e Wes t Virginia ’s preclusion law, see Brief f o r Petiti oners 15–16, where a s Bayer favo rs looking only to federal rules of prec lusion because of the federal inter

ests at stake i nth is c a se, se e Br ief for Respondent 18. We do not thi n k the question matters here. Neither party identifies any way in which federal and state principles of prec lusio nlaw differ i nany relevant res p ect
. Nor have we fou n d a n y s u ch divergen ce. Com p a r e, e.g. , Montanav. Un i t e d S t a t es , 440 U. S. 1 4 7 , 153– 154 ( 1 9 79) (desc r ibin g elements of i s sue preclusion), with Statev. Miller, 194 W. Va. 3, 9, 4 59 S. E. 2d 1 14, 1 20 (1 99 5) (s a m e). Wetherefore need not decide whether, in general, federal commo n law ought to incorporate st ate l a w in s i tuations s u ch as this

.

7 Because we rest our decisi on onthe Anti-Injunc tion Ac t and the principles of issue preclu sion that inform it , we do not consider Smi t h’s ar g u men t , based on Phillips Petroleum Co. v. Shutt s , 472 U. S. 79 7 (198 5), th at th e Distr i c tCou r t’ s ac ti on violated the Due Process Clause.8 SM ITH v. BAYER CORP. Opinion of theCourt 

### A In our most recent ca se on the r e litigation exception, Chick Kam Choo v. Exxon , we a pplied the “same issu e” requiremen tof preclusion law t o invalidate a federa l court’s inju nction. 486 U. S., at 151. The federal court had dismissed a suit involving Si ngapore law on grounds of forum non conveniens

. After t h e plaintiff brought th e same claim in Texas s t ate court, the federal court issued an injunction barring the plaintif f from pursuing relief in that alternate forum. We held that the Distr i ct Court h a d gone too far

. “[A]n ess e ntial prerequisite for applying th e relitigation exception,” we explai ned, “is th at the .

. . is

sues which the federal injunction insulates from litigation in state proceedings actually have been decided by the federal court.” Id. , at 1 48. That prerequisite, we thought, was not sa tisfied because the issue to be adjudicated in state court was not the one the federal court h a d resolved. The federalcourt had considered the permiss ibility of th e claim under federal forum non conveniensprinc i p l es. B u t the Texas courts, we thought, “wo u ld apply a significantly different forum non conveniens an alysis,” id. , at 149; they had in prior cases rej e cted the s trictness of the federal doctrine. Our conclu sion followed: “[W]hether the Texas sta t e courts are an appropriate forum for [th e plaintiff’s] Singapore law claims has not yet been litig ated.” Ibid. Because the legal standards in the two courts differed, the issues before the courts differed, and an injunction was unwarran t ed. The questi o n here cl o s ely resem b les the on e in Chick Kam Choo. The class Smith proposed in state court mir

rored the cl ass McCollins sought to certify in federal court: Both inclu d ed all Ba ycol pur c h a sers resident in West Virginia. Moreover, the substantive claims in the t w o suits broadly overlapped: Both complaints alleged that Bayer had sold a defective product in violation of t h e State’s consumer protection law and the co mpany’s war

-9 Cite as: 56 4 U

. S. ____ (2011) Opinion of theCourt 

### ranties. So far, so goo dfor preclusion. But not so fast: a criticalquestion—the question of the appl icable legal standard—remains. The District Court ru led that th e proposed class did not meet the requirement s of Federal Rule 23 (because individualized iss u es would predominate over common on es). But the state court was poised to consider whether the proposed class satisfied Wes tV i r ginia Rule 23. If those two legal standards differ (as federal and state forum non conveniens la w differed in Chick Kam Choo )—then the federal court resolved an issue not before the state court. In that event, much like in Chick K a m Choo , “ w hether th e [West Virginia] st ate cour[t]” sho u ld certify the proposed class acti on “has not yet been litigated.” 486 U. S., at 14 9. The Court of Appeals and Smith offer us two competin g ways of dec i ding whet her the West Virginia and Federa l Rules differ, but we thi n k the rightpath lies somewhere in the middle. The Eighth Circuit relied almos texclusively on the near-identity of the two Rul e s’ texts. See 593 F. 3 d , at 723. That was the right place to start, bu t not to end. Federal and state courts, after all, can and do apply iden

tically worded procedural pr ovisions inwidely varying ways. If a State’s procedur al pr ovision tracks the lan

guage of a Federal Rule, but a state court interprets that provision in a manner federal courts have not, then the state court is using a different standard an d thus decidin g a different issue. See 18 Wright & Miller §4417, at 454 (stating tha tpreclusion is “inappropriate” whe n“different legal standards .

. . masquerad[e] behind similar legal labels”). Atthe other extreme, Smith contends that the source of law is all that matter s : a different sovereign m u s ti ne a c ha n de v e r yc a s e “have the opportunity, if it chooses, to construe its procedur alrule differently.” Brief for Petitioners 22 (qu o ting ALI, Principles of the La w, Aggr egate Litigation §2.11, Reporters’ Not e s, cmt. b , p. 181 (2010)). But if state courts have made crys t al clear10 SM ITH v. BAYER CORP. Opinion of theCourt 

### that they f o llow the same approach as the federal court a p p l i e d , w e s e e n o n e e dt o i g nore that determination; in that event, the issues i nthe two cases would indeed be t h e same. So a federal court co nsidering whether the relitiga

tion exception applies should examine whether state law parallels its federal counterpart. But as suggested earlier, see supra , at 6, the federal court must resolve any uncer

tainty on that score by leaving the questionof preclusion to the state courts. Under this approach, t h e West Virginia Supr eme Court has gone some way to ward re solving the matter before us by declaring its independence from federal courts’ inter

pretation of the Feder a l Rules—and particul a rly of Rule 23. In In re W. Va. Rezulin Litiga tion, 214 W. Va. 52, 585 S. E. 2d 52 (2003) (In re Rezulin) , the West Virginia high court considered a plaintiff’ s motion to certify a class— coincidentally enough, in a suit about an allegedly defec

tive pharmaceutical product. The court made a point of complaining about the parties’ and lower court’s near

exclusive reliance on f e deral cases about Federal Rule 2 3 to decide the certification quest ion. Such cases, the court cautioned, “ ‘may be persuasive, but [they a r e] not bindin g or controlling.’ ” Id. , at 61, 585 S. E. 2d, at 61. And les t anyone mistake the import of this message, the court went on: The a i m of “this rule is toavoid having our leg a l analysis of our Rules ‘amount to nothing more than Pa v lovian responses to federal decisional law.’ ” Ibid. (italics omitted)

. Of course, the state courts might still have adopted anapproach to their Ru le 23 that trac k ed the analysis the federal court used in McCollins’ case. But absent clear evidence that the state courts had done so, we could not conclude that they would interpret their Rule in the same way. And if t hat is so, w e could not tell whether the certifica tion issues in the state and federal courts were the same. That uncertainty would preclude an injunction. But here th e case against an injunction is even stronger,11 Cite as: 56 4 U

. S. ____ (2011) Opinion of theCourt 

### because the West Virginia Supreme Court has disap

proved the approachto Rule 23(b)(3)’s predominance requirement that the Federa l District Court embraced

. Recall that the federal court held that the presence of a single i n dividualized issue—i n jury from the use of Baycol—pre vented class certi f icatio n. See supra , at3. Th e court did n o t identify the common issues in the case; nor did it balance these common iss u es against the need t o prove individual injury to determine which pre d ominated. The court instead applied a strict test barringclass treat

ment when proof of each plaintiff’s injury is necessary. 8 

### By contras t , the West Vir ginia Supreme C o urt in In re Rezulin adopted an all-thin gs-considered, balancin g inquiry in interpreting its Rule 23. Rejectin gany “rigi d test,” the state court opined that the predominance re

quirement “contemplates a review of many factors.” 21 4 W. Va., at 7 2 , 585 S. E. 2d, at 72. Indeed, the court noted, a “ ‘single common i s s u e’ ” in a c a se could outweigh “ ‘n u merous . . . individual questions.’ ” Ibid. Tha tmeant, the court fur t h e r explained (quoting what it ter m ed the “lead

ing treatise” on the subject), thateven objections to certifi

cation “ ‘bas ed on .

. . causation, or reliance’ ”—w h ic h t y pi

cally involve showings of individual injury—“ ‘will not bar predominance satisfacti on.’ ” Ibid. (quoting 2 A. Conte & H. Newberg, Newberg on Class Actions §4.26 , p. 241 (4t h ed. 2002))

. So point forpoint, the analysis setout in In re Rezulindiverged from the Distri ct Court’s interpretatio n of Federal Rule 23. A state court using the In re Rezuli n standard would decide a different question than the one

——————

8 The Distr i c tCour t’ s appr oach to th e p r edominance inquiry is co nsis

tent with the approach emp l oyedby the Eighth Circuit. See In re St. Jude Me dical, Inc. , 522 F. 3d 8 36, 8 3 7

– 8 40 (2 00 8) (h ol din gth at mo s t com m e rcia lmis r epres e nt a t ion ca s e s a r e “ uns uit ab l e for cla s s t r ea t

ment” because individual issues of reliance necessarily predominate). We express noopinion as to th e correctnes s of this approach.12 SM ITH v. BAYER CORP. Opinion of theCourt 

### the federal court had earlier resolved. 9 

### This case, indeed, is little more than a rerun of Chick Kam Choo

. A federal court and a state court apply differ

ent law. That means they decide distinct questions. Th e federal court’s resolution of one iss u e does not preclude the state court’s determination of an other. It then goes wi th

out saying that the federal court may not issue an injunc

tion. The Anti -Injuncti on Act’s re -litigation exception does not extend nearly so far. B The injunction issuedhere runs into anoth er basic premise of preclusion l a w: A court’s judgment binds on ly the parties to a suit, s ubject to a handful of discrete an d limited exceptions. See, e.g. , 18A Wright & Miller §444 9, at 330. The importance of this rule and the n a rrowness of its exceptions go hand in hand

. We have repeatedly “em

phasize[d] the fundamental nat ure of the general rule” that only parties can be bound by prior judgm e nts; accord

ingly, we have taken a “constrained approach to nonparty preclusion.” Taylor v. Sturgell , 55 3 U. S. 880, 898 (2008). Against this backdrop, Bayer defends the decision below by arguing that Smith—an unn amed member of a pro

-

——————

9 B a yer a r gues t h a t In re Rez u lin does not preclude an injunction in t h is ca s eb e caus e t h e Wes tVirginiacourtt h ere de cided t h a tcom m o n issues predominated overindividual issue s of damages, not over indi

vidual issues of liabi lity (a s exist he re). See Brief for Respondent 25– 26. We th in k Bay e ris r i gh t abou tth i s di st in c t ion , bu t wr on gabou tits cons eq uence. Our point is not tha t In re Rezulindictates the answe r t ot h e cla s s cert ifica t ion q u es t i on h e r e ; th etw oca s e s are indeed too dissi mil a rforthat to be tr ue . The point instead is tha t In re Rez u li n a r t i cula t e d a genera l a ppro a ch t o the pre d ominance re quirement that differs marke d ly from the one the fe dera l courtus ed. M i nor va ria t ions in the application of what is in e ssen c e the same leg a l s t an dar ddo n o t defeat preclusion; but where , as here , the Sta t e’ s c o ur ts “would apply a s i gnifica n t l y different

. . . a n a l ys is ,” Chick Kam Choov. Exxon Corp

. , 486 U. S. 1 40, 149 ( 198 8), t h e feder a l an d sta t e c o u r ts dec i de differ e n t issu es.13 Cite as: 56 4 U

. S. ____ (2011) Opinion of theCourt 

### posed but uncertified class—qualifies as a party to the McCollins l i tigation. See Brief for Respondent 32–34. Alternative l y, Bayer claims that the District Court ’ s judgment b i nds Smithunder the recognized exception to the rule against nonparty preclusion for members of class actions. See id ., at 34–39. We t h ink neither contention has merit. Bayer’s fi rst claim ill-comports wi th any pro p er under

standing of what a “party” is. I ngeneral, “[a] ‘party’ to litigation is ‘[o]ne by or against whom a lawsuit is brought,’ ” United S t a t es ex rel. E i sens t einv. City of New York , 556 U. S. ___, ___ (2009) (slip op., at 4), or one who “become[s] a party b y intervention, substitution, or third

party p r act i ce,” Karch erv. May , 484 U. S. 72, 77 (1987 ). And we ha ve further held that an unnamed member of a certified class may be “considered a ‘party’ for the [particu

lar] purpos[e] of appealing” an adverse judgment. Devlin v. Sc ardell e tti , 536 U. S. 1, 7 (200 2). But as the dissent in Devlinnote d, no one i nthat case was “willing to advance the novel and surely erroneous argument that a no n named class member is a party to the class-action litiga

tion before the cla ss i sc ertifi ed. ” Id. , at 16, n. 1 (opinion of S CALI A 

### , J.). Still l e ss d oes that argument make sens e onc e certificationis deni ed

. The definition of the term “pa rty” can on no account be stretched so far as to cover a person like Smith, whom the plaintiff in a lawsuit was denied leave to represent. 10 

### If the judgment in the McCollins

——————

10 In s u pportof i t s cla i mt h a t Sm it h count s a s apa rt y, Ba yer cit e s t w o cases in which we held that a putative mem b er of a nu n cert ified cla ss maywait until afterthe c o ur t r u les on thecertification motion to file an indiv i dual c l ai m ormov eto i n terv en ein the suit. See Brief for Respon

den t32 –33 (c itin g United Airlin es, Inc. v. McDonald , 432 U. S. 38 5 (197 7); Americ a n Pipe & Constr. Co. v. Utah , 414 U. S. 5 3 8(19 74)). Bu t these case s, which we re specifically grounded in poli cies of judicial adminis t r a tio n , demonstr ate onlythat a per s on not a par t yto a c l as s suit m a y receive certain be nefits (such a s the tolling o f a l i mi tat i ons period) relate d to that pro c eeding. See id., at 55 3; McDo n ald , 43214SM ITH v. BAYER CORP. Opinion of theCourt 

### litigation can indeed bind Sm i t h , i tm u s td o s o u n d e r principles of non party preclusion. As Bayer n o tes, see Brief for Respondent 37, one such principle allows unna med memb ers of a cla ss action to be bound, even though they are not parties to the suit. See Cooper v. Feder a l Re serv e Bankof Richmond , 467 U. S. 867, 874 (1984) (“[U]n der elemen tary princi ples of prior adjudicatio na judgme nt in a pro p erly entertained class action is binding on class members in any subsequent litigation”); see als o Taylor , 553 U. S., at 894 (stating that nonparties can be bound in“properly conducted clas s actions”). But here Bayer faces aconundru m. If we know one thing about the McCollins sui t , we kno wthat it was nota class action. Indeed, the very ruling that Bay e r argues ought to be given prec lusive effect is the District Court’s dec i sion that a class could not properly be certi

fied. So Ba yer wan t s to bind Smith as a member of a class action (because it is only as su ch that a nonparty i n Smith’s situation can be bound) t o a determ ination th at there could not be a class action. And if the logic of that position is not immedi ately transparent, here is Bayer’s attempt to clarify: “[U] ntil the moment when class certi

fication wa s denied, the McColli nscase wa s a properly conducted class action. ” Brief for Respondent 37. That is true, according to Bayer, because McCollin s’ interests were aligned with the members of the class he proposed and he “act[ed] in a representative capacit ywhen he sought class certification.” Id., at 36. But wishing does not make it so. McCollins sought class certification, but he failed to obtain that result. Because the DistrictCourt found that ind i vidual issues predomi

-

—————— U. S., at 394, n

. 15. T h at result is consis tent with a co mmonplace of preclusion law—that nonparties someti mes may ben e fit from, even th ou ghth eycan n o t be bou n dby , for m er litig at ion

. See Parklane H o siery Co. v. Shore , 439 U

. S. 322, 32 6–33 3 (19 79); Blonder- Tong u e Lab o ratories, I n c. v. Universi ty of Ill. Foundation , 402 U. S. 313 (19 71).15 Cite as: 56 4 U

. S. ____ (2011) Opinion of theCourt 

### nated, it held that the action did not satisfy Federal Rule 23’s requirements for class proceedings. In these circum

stances, we cannot sa y that a properly conducted class action existed at any time in the litigation. Federal Rule 23 determines what is and is not a class acti on in federal court, where McCollins brought his suit. So i nthe absen ce of a certification under that Ru le, the precondition for binding Smith was not met. Neither a proposed class action nor a rejected class a ction may bind nonparti es. What does have this effect is a class action approved under Rule 23. But McCollins’ lawsuit was never that. We made essentially these same points in Taylor v. Sturgell jus ta few Terms ago. The questionthere con

cerned the propriety of binding no nparties under a theory of “virtual representation” based on “identity of interest s and some kind of relationship b e tween parties and non

parties.” 553 U. S., at 901. We rejected the theory unanimously, explaining that it“would ‘recogniz[e], in effect, a common-law kind of class action.’ ” Ibid. Such a device, we objected, would autho rize preclusion “shorn of [Rule 23’s] procedural protections.” Ibid. Or as otherwise stated in th e opinion: We could not allow “circumvent[ion]” of Rule 23’s protections througha “virtual rep r esentation doctrine th at allowed courts to ‘c reate de facto class ac

tions at wi ll.’ ” Ibid. We cou l d hardly have been mor e clear that a “properl yconducted class action,” withbin d

ing effect o nnonparties, can come about in fe deral courts in just one way—through the procedure set out in Rule 23. Bayer atte mpts to distinguish Taylor by not i ng that the party in th e prior litigation there did not propose a class action. Bu t we do not see why that differe nce matter s . Yes, McCol lins wishedto represent a class, and made a motion to that effect. But itdidnot come to pass. To allow McCollins’ suit to bind nonpa rties would be to adopt16 SM ITH v. BAYER CORP. Opinion of theCourt 

### the very the o ry Taylor r ejected. 11 

### Bayer’s s t rongest argu ment comes not from established principles of preclusion, but instead from policy concerns relating to use of the class action device. Bayer warns that under our approach class counsel can r e peatedly try to certifyt h e same class “by th e simple expedient of changing the named plaintiff in the caption of the com

plaint.” Bri e f for Respondent 47–48. And in this world of “serial relit igation of c l ass certification,” Bayer contends, defendants “would be forced in effect to buy litigation peace by s e ttling.” Id

. , at 2, 1 2 ; see also In re Brid ge stone/Fi restone, Inc., Tires Prods. Liability Litiga tion , 333 F. 3d 7 63, 767 (CA7 2003) (objecting to an “an asym

metric system in which class counsel can win but never lose” because of their ability to relitigate the issue of certification). But this form of argu ment flies in the face of the rule against nonparty precl u sion. That rule perforce leads to relitigation of many issues, as plaintiff after plaintiff after plaintiff (none precluded by the last judgment because none a party to the last suit) tries his hand at establishin g some legal principle or obtaining some grant of relief. We confronted a similar policy concern in Taylor , which in

volved litigation brought unde rthe Freedom of Infor

-

——————

11 The great weight of scholarly au thority—from the Restatement of Judgments to the America nLaw Instit ute to Wright and Miller— agr ees th at a nu n c er tified c l ass actioncannot bindproposed class member s. See Rest atemen t(Sec on d) of Ju dg men t s §41( 1), p. 393 ( 1 9 8 0 ) (A nonpa r ty ma y b eb o und only whe n his interes t s a r e a d eq ua tely r e pr esented b y“[t]he r e pr esentativ eof a class of persons similarly situ ate d , desi g n ated as su c hwi th the approval of the court ” ); ALI , Principles of the Law Aggregate Liti gatio n§2.11, Re porters’ Notes, cm t. b , p. 181 (201 0) (“[N]on eof [th eex c e ption s to th e ru le again s t n o n p ar ty preclusion] extend generally to the si tu a t i o nof a wou l d-be ab sen tc l as s memberwith r e spec t to a denial of c l ass c e r t ific ation”); 18A Wr ight & Miller §4455, at 45 7– 45 8 (“[A]bsent certifi c ation there is no basi s for precludingan o npa r ty” unde rthe cla s s - a c tion ex ception).17 Cite as: 56 4 U

. S. ____ (2011) Opinion of theCourt 

### mation Act (FOIA). The Government there cautioned that unless we bound n o nparties a “ ‘potentially limitless’ ” number of plaintiffs, perhaps coordinating with ea ch other, could “mount a series of repetitive lawsuits” d e manding th e selfsame documents. 553 U. S., at 903. Bu t we rejectedthis ar gu ment, even though th e payoff ina single successful FOIA suit—dis closure of documents to the public—could “trum[p]” or “s ubsum[e]” all prior losses, just as a single successful class certification motion could do. In re Br idges t one/F i res tone , 33 3 F. 3d, at 7 66, 767. As that response suggests, our legal system generally relies on principles of stare decisi s andcomity among courts to mitigate the sometimes substantial costs of s i milar litig a tion brough t by different plaintiffs. We have not thought that the righ t app r oac h(exceptin the discr e te categori es of cases we have recogn ized) lies in binding nonparties to a judgment. And to the extent class actions raise special problems of relitigation, Congress has provid ed a remedy that does not involve dep a rting from the usual rules of preclusion. In the Class Action Fairn e ss Act of 2 005 (CAFA), 28 U. S. C. §§1332(d), 1 453 (2006 ed. and Supp. III), Congress enab led defendants to remove to fede ral court anysizable class action involving minimal divers ity of citize nship. On ce removal takes place, Federal Ru le 23 governs certification. And federa l courts ma y conso lidate multiple overlapping suits against a single defendant in one court (as the Judi

cial Panel on Multi-District Litig a tion did for the many actions involving Baycol). See §1407. Finally, we woul d expect fede ral courts t o apply p r inciples of comity to each other’s class certification de cisi on s when ad dressing a common dis p ute. See, e.g., Cortez Byrd Chips , Inc. v. Bill Harb er t Co nstr. Co. , 529 U. S. 193, 198 ( 2000) (citing Landisv. N o rth Americ a n Co. , 299U. S. 248, 254 (1936)). CAFA maybe cold co mfort to Ba yer wi th re spect to sui t s like this one beginning before its enactment. But Con

-18SM ITH v. BAYER CORP. Opinion of theCourt 

### gress’s deci sion to address th e relitigation concerns associ

ated with class actions through the mechanism of removal provides yet another reason fo r federal courts to adhere in this context to longstanding principles of preclusion. 12 

### And once again, that is especially so whenthe federa l court is dec i ding whet her to go so far as to enjoin a stat e proceeding. * * * The Anti-Injunction Ac t prohibits the order t h e Distric t Court enter e d here. The Act’s relitigation exception au

thorizes injunctions only when a former federal adjudica

tion clearly precludes a state-court decision. As we sai d more than 40 years ago, and have consistently maintained since that time, “[a]ny doubts .

. . should b e resolved in favor of permitting the state courts to proceed.” Atlanti c Coast Lin e , 398 U. S., at 297. Under this approach, close cases have easy answers: The federal court should not issue an inj unction, and the state court should decide the preclusion question. But this case does not even strik e us as close. The issues in the fed e ral and st ate lawsuits differed because the relevant legal standa r ds differe d. And the m e re proposal of a class in the federal action could not b i nd persons who were not parties there. Fo r these reaso n s, the judgment of the Court of Appeals is Reversed.

——————

12 Bythe same token, nothing in ou r holding today foreclos es legisla

tion to mo dif yestab lishedpr inc i pl es of preclusion should Congre ss decide that CAFA does not sufficien tly prevent relitigation of clas s certification m o tions. Nor d oes this opinio n at a ll address the permis

sibi lity of a ch ange in the Federal Ru les of Civil Procedure pertaining to this ques tion. Cf. n. 7, supra(declining to reach Smith ’ s due process cla i m)

.